Environmental determinants and controls of skin color change in neotropical anurans

Physiological color change is a strategy present in many groups of vertebrates and invertebrates. Animals showing this behavior have become model taxa in the study of camouflage because they are able to respond dynamically to changes in the environment. A number of studies have looked at the ability of amphibians to change skin coloration, in a phenomena known as physiological color change. In the physiological response, dermal pigment-containing cells rapidly react by modifying the distribution of pigments. Environmental factors such as light intensity and background color have been known to be very important cues on amphibian physiological color change, but the ecological function of these changes, in the context of a changing environment, is still unclear. Additionally, due to the presence of visual pigments in chromatophores, amphibians can aggregate or disperse pigments in specific areas of the skin, as a direct response to changes in the intensity of light; response that raises new questions about the benefits and drawbacks than an (visually) uncontrolled change might have on anuran ecology. However, studies have been limited to early stages. This study investigates how environmental factors affect color change in anurans and to what extent these changes are controlled by the individual. First, I present a review of the importance of coloration for anuran ecology and discuss the current issues dealing with color change experiments (Chapter I). Then, I present the results of the first experiment, in which I tested the ability of the Panamanian frogs Gastrotheca cornuta and Strabomantis bufoniformis to change skin coloration in response to light intensity and background coloration (Chapter II). I show that both species respond to changes in light and background color, but there are interspecific differences, probably due to the species-specific habitat characteristics (i.e. Forest canopy and floor respectively). Then, in a second experiment on Hypsiboas rosenbergi adults, I demonstrate the ability to change skin coloration as a direct, visually uncontrolled and localized response to light. These findings suggest that changes in adult frog skin coloration play an important role in camouflage and thermoregulation, and give a key, yet missing, component in understanding the behavioral and evolutionary implications of color change in animals

Estudio de la adsorcion de cromo hexavalente como biomaterial la ectodermis de opuntia

En este artículo se presenta el fenómeno de adsorción química como una opción viable en el tratamiento de aguas residuales que contiene disueltos iones metálicos, específicamente se aborda el estudio del Cromo Hexavalente, el cual se puso en contacto con el biomaterial de Ectodermis de Opuntia. Dicho biomaterial se puso en contacto con soluciones de dicho elemento solo y formando un complejo coloreado con la difenilcarbazida (DFC), esto con la finalidad de estudiar el comportamiento de la adsorción, para lo cual se realizaron las cinéticas respectivas y se calcularon las isotermas de adsorción de los modelos de Langmuir y Freundlich. Los resultados mostraron que el biomaterial sin un tratamiento químico de acidificación muestra una adsorción máxima del 50% del ión metálico y a su vez formando el complejo ya señalado el porcentaje de remoción máximo fue del 40%.En este artículo se presenta el fenómeno de adsorción química como una opción viable en el tratamiento de aguas residuales que contiene disueltos iones metálicos, específicamente se aborda el estudio del Cromo Hexavalente, el cual se puso en contacto con el biomaterial de Ectodermis de Opuntia. Dicho biomaterial se puso en contacto con soluciones de dicho elemento solo y formando un complejo coloreado con la difenilcarbazida (DFC), esto con la finalidad de estudiar el comportamiento de la adsorción, para lo cual se realizaron las cinéticas respectivas y se calcularon las isotermas de adsorción de los modelos de Langmuir y Freundlich. Los resultados mostraron que el biomaterial sin un tratamiento químico de acidificación muestra una adsorción máxima del 50% del ión metálico y a su vez formando el complejo ya señalado el porcentaje de remoción máximo fue del 40%

Archaeofaunas and intensification process during the sierras of Córdoba late prehispanic period (Argentina): The Arroyo Talainín 2 site

En este trabajo se presentan los resultados del estudio zooarqueológico realizado sobre los restos de vertebrados recuperados en las excavaciones del sitio prehispánico tardío Arroyo Talainín 2 (Córdoba, Argentina), un abrigo rocoso cuyo talud e interior presentó más de 21.000 restos faunísticos. El conjunto está dominado por cáscaras de huevo de ñandú (Rheidae), con una representación inusualmente densa que se aleja de los patrones regulares observados en otros sitios de la región. Lama sp. y Cervidae ocupan un lugar secundario, con una mayor representación de los elementos axiales, justamente aquellos que son escasos o ausentes en los sitios interpretados como poblados semi-sedentarios. También presentan en promedio una mayor proporción de partes de alto rendimiento. Sitios como Arroyo Talainín 2 indican que una porción significativa de los recursos explotados durante el Período Prehispánico Tardío -y con frecuencias totalmente distintas- se procesaba, consumía y descartaba recurrentemente en contextos extracomunitarios dispuestos para tal fin, en donde interactuaban numerosas personas y/o grupos fortaleciendo lazos sociales. Se concluye que los cambios observados en el registro arqueológico ca. 1100 AP, más allá de la incorporación de cultígenos y la diversificación de la caza-recolección, también involucraron la intensificación de las relaciones sociales, visible arqueológicamente a partir de la composición de los conjuntos faunísticos y artefactuales. Por último, se destaca la importancia del Número de Especímenes Identificados por taxón (NISP) para cuantificar procesos de intensificación económica a partir de restos óseos altamente fragmentados.This paper present the results of the zooarchaeological study carried out on the Late Prehispanic site Arroyo Talainín 2 (Córdoba, Argentina), a rock-shelter with 21000 faunal remains in its deposits. The assemblage is dominated by South-American ostrich eggshells (Rheidae), with an unusually dense representation far from the pattern observed in other regional sites. Lama sp. and Cervidae were secondary exploited on site, showing a high mean utility of skeletal parts and high frequency of axial anatomical elements, those which are scarce or absent in semi-sedentary summer villages. Sites as Arroyo Talainín 2 indicate that a significant portion of the late prehispanic resources included in the subsistence were processed, consumed and discarded regularly in sites associated with large-group food processing and consumption at comunitary level, where social bonds were strengthened. It is concluded that the change observed in the archaeological record ca. 1100 BP with the adoption of a mixed farming and cultivation economy also involved the intensification of social relations, archaeologically visible throught the composition of faunal and artifact assemblages. Finally, the importance of the Number of Identified Specimens per Taxón (NISP) to quantify the economic intensification process in fragmented bones assemblages is highlighted.Fil: Medina, Matias Eduardo. Centro de Estudios Históricos "Profesor Carlos S. A. Segreti"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Propuesta de mejora en la gestión de la producción de semirremolques plataforma para reducir los costos operacionales en la empresa Construcciones y Servicios Metálicos S. A. C.

El autor no autoriza la publicación de la tesis

Initial and Advanced Stages of Microbiota Establishment within the Tsetse Fly

Symbiosis is a long-term physical association between two or more species, although little is known regarding its evolutionary origins, particularly at the genetic level. Tsetse flies are the vector of African trypanosomes, causative agents of Human and Animal African Trypanosomiases. Tsetse provide an ideal model for studying initial and advanced stages of symbiosis. Tsetse have a simple digestive tract microbiota primarily consisting of two bacteria; the ancient mutualist Wigglesworthia glossinidia and the recently acquired Sodalis glossinidius. This work presents a chronological study in evolutionary terms of the history of a microbial-insect association. First, I present concepts on symbiosis and comments on tsetse and their native microbiota. Second, I focus on early evolutionary transition of an environmental bacterium to a symbiotic lifestyle. I show that quorum sensing virulence suppression facilitates the establishment of Sodalis-allied symbionts in diverse insects. Third, I compare the metatranscriptome of teneral Glossina morsitans (high vector competence) to that of Glossina brevipalpis (low vector competence). The transcriptomes of Wigglesworthia and Sodalis reflect differences in the extent of co-evolution with tsetse and identify pathways that may contribute towards distinctions in vector competence. Fourth, I present a theoretical mechanism by which microbial symbionts may control gene expression in insect host via epigenetics. I propose a link between the folate provisioning roles of the microbiota and the health of blood-feeding insects, via DNA methylation. This work reflects the use of a combined approach to gain a comprehensive understanding of symbiosis evolution, its mechanisms and its potential to impact epidemiology

Deep CNN and MLP-based vision systems for algae detection in automatic inspection of underwater pipelines

Artificial neural networks, such as the multilayer perceptron (MLP), have been increasingly employed in various applications. Recently, deep neural networks, specially convolutional neural networks (CNN), have received considerable attention due to their ability to extract and represent high-level abstractions in data sets. This work describes a vision inspection system based on deep learning and computer vision algorithms for detection of algae in underwater pipelines. The proposed algorithm comprises a CNN or a MLP network, followed by a post-processing stage operating in spatial and temporal domains, employing clustering of neighboring detection positions and a region interception framebuffer. The performances of MLP, employing different descriptors, and CNN classifiers are compared in real-world scenarios. It is shown that the post-processing stage considerably decreases the number of false positives, resulting in an accuracy rate of 99.39%.Redes neurais artificiais, como o perceptron multicamada (MLP), têm sido cada vez mais empregadas em várias aplicações. Recentemente, as redes neurais profundas (deep neural networks), especialmente as redes neurais convolutivas (CNN), receberam atenção considerável devido à sua capacidade de extrair e representar abstrações de alto nível em conjuntos de dados. Esta dissertação descreve um sistema de inspeção automático baseado em algoritmos de aprendizado profundo (deep learning) e visão computacional para detecção de algas em dutos submarinos. O algoritmo proposto compreende uma rede CNN ou MLP, seguida de uma fase de pós-processamento que opera em domínios espaciais e temporais, empregando agrupamento de posições de detecção vizinhas e um buffer das regiões de interseção ao longo dos quadros. Os desempenhos de MLP, empregando diferentes descritores, e os classificadores CNN são comparados em cenários do mundo real. Mostra-se que a fase de pos-processamento diminui consideravelmente o número de falsos positivos, resultando em uma taxa de acerto de 99,39%

An analysis of sustainable marketing and how is managed through social media platforms.

This paper provides the analysis of sustainable marketing and how is managed through social platforms. Globalization and the rise of the digital era have allowed companies to put more effort in their sustainability practices. Therefore, it is important to know that consumers are smarter more demanding, thus, brands a creating relevant content to share their corporate share values. The data has been gathered from number of website’s articles, previous studies, books and videos. The current study has been an attempted to build knowledge and to understand the importance of how sustainable brands such as Weleda, Patagonia, Whole foods, McDonalds, Alo Yoga developed their strategies through social media to promote engagement to consumer.However, beyond creating engagement, brand need to consider other strategies though examine the customer journey. The findings of this research demonstrated that other sustainable brands create engagement by creating share value. Thus, relevant content can build a strong and long relationship between the brand and consumers. According to Cocking (2019) storytelling has become fundamental for this practice based on entertainment, learning, brand promotion and more. This evidence is shown by Kiepura (2017) with his example of Footprint Chronicles by Patagonia communicating their supply change problem with higher level of transparency. On the other hand, (USG) shown that creating the Hashtags #AloGivesWater and #cartgoals helped brands such as Alo yoga and Whole Food to connect with their audiences and build awareness. In overall, when planning a customer journey, sustainable brands are developing a model of experience economy. However, each interaction in the costumer journey will make a difference for the next step to satisfy consumer needs an understand consumer behaviours. As a result, brand can put more effort with their practices and build awareness between the consumers and the brand

Geração radiativa de repulsão vetorial para quarks leves

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Programa de Pós-Graduação em Física, Florianópolis, 2014Abstract: We apply a non-perturbative analytical method, known as the Optimized PerturbationTheory (OPT), to the Polyakov-Nambu-Jona-Lasinio (PNJL) model in order to investigate physical quantities associated with the QCD phase transitions. We consider the Taylor expansion of the pressure in powers of µ/T obtaining the second cumulant (c2) which is associated to the quark number susceptibility. We discuss how the OPT nite Nc radiative (quantum) corrections induce a contribution to the pressure which behaves as a vector repulsion even when such a channel is absent in the original classical potential. Our results are then compared with the ones furnished by lattice QCD simulations and by the large-Nc approximation showing that, physically, the OPT results resemble those furnished by the latter approximation when a repulsive vector channel is explicitly included in the classical potential. In this case, both approximations fail to correctly describe the Stefan-Boltzmann limit at high temperatures. We discuss how this problem can be circumvented by taking the couplings to be temperature dependent so as to simulate the phenomenon of asymptotic freedom. Since this is the first time the OPT is applied to the PNJL we also discuss many technicalities associated with the evaluation of two loop (exchange) diagrams.Neste trabalho o método analítico não perturbativo conhecido como Teoria de Perturbação Otimizada (OPT) é aplicada ao modelo de Polyakov-Nambu-Jona-Lasinio (PNJL) para que quantidades físicas, associadas com as transições de fase da QCD, possam ser calculadas. A expansão da pressão em potências de µ/T é considerada para obter o segundo cumulante (c2) que é uma quantidade relacionada com a susceptibilidade do número de quarks. Primeiramente discutimos como as correções radiativas de Nc finito geradas pela OPT produzem uma contribuição que se comporta como um termo vetorial repulsivo mesmo quando este tipo de canal está ausente no potencial clássico original. Em seguida, nossos resultados são comparados com aqueles fornecidos pelas simulações na rede e também pela aproximação de Nc grande(LN). Fisicamente, os resultados da OPT são similares aqueles fornecidos pela aproximação LN quando um canal vetorial repulsivo é explicitamente incluido no potencial clássico. Neste caso, nenhuma destas aproximações analíticas produz corretamente o limite de Stefan Boltzmann para altas temperaturas. Contudo, nossos resultados sugerem como estes problemas podem ser contornados tomando-se as constantes de acoplamento como sendo dependentes da temperatura, de maneira que o fenômeno da liberdade assimptótica possa ser simulado. Esta é a primeira vez que a OPT é aplicada ao modelo de PNJL e por isto vários aspectos técnicos relacionados com o cálculo de diagramas de dois laços são também aqui apresentados

STRUCTURAL ANALYSIS OF VALLES MARINERIS, MARS

Valles Marineris is the largest canyonland formation known in the solar system being ~4000 km long and up to 11 km deep, it is subparallel to the Martian equator and exposes the interior of the Tharsis province. The spurs on the walls were analyzed using digital elevation models to geometrically quantify their morphology and orientation, relying on methodologies such as dip analysis, relief and curvature analysis, and attitude analysis among others. These analyses permitted the documentation of indicators of structural influence on the walls which were then classified by the morphology and the type of faults from which they originate. Anomalous Planes (APs) are planar features that dip into the walls of a chasma and appear to be pre-existing fault planes within the Tharsis province. These faults are associated with the underlying structures of the Large Wrinkle Ridges (LWRs) located on Ophir Planum. An elastic dislocation model was used to corroborate that the APs can define the geometry of the underlying structure of the LWRs. Planetary grabens can be distinguished from sapping channels using their geometries. It is proposed that the formation of Coprates Chasma was the result of four individual smaller chasmata that later joined. This work shows the tools and criteria used to demonstrate that the formation of Valles Marineris was complex as reflected in the formation of the wall morphology. It is shown that the formation of the walls was influenced by pre-existent structures and chasma producing faults

Resistant practices, avoidance, and social reproduction in an adverse historical context: looking at the indigenous from Córdoba (Argentina) in early colonial times

La investigación se desarrolla en el marco de la arqueología histórica, concebida como el estudio del proceso de modernización que siguió a la expansión europea. Se analiza el caso de un sitio arqueológico, el Alero Tala Huasi, ocupado desde momentos previos a la conquista española hasta el Período Colonial Temprano -fines del siglo XVI y primera mitad del XVII. La persistencia de prácticas económicas, tecnológicas y rituales de raíces prehispánicas así como la incorporación selectiva de elementos foráneos, como el ganado euroasiático consumido en el lugar, son interpretadas en clave de resistencia y elusión de las relaciones de dominación impuestas, en un intento por mantener y reproducir la integración grupal. Se destaca la potencialidad de la arqueología histórica para indagar sobre procesos sociales al margen de los registros escritos, al entender aspectos de la vida cotidiana y de la agencia de colectivos invisibles en el discurso oficial de la sociedad colonial.Fil: Pastor, Sebastián. Centro de Estudios Históricos "Profesor Carlos S. A. Segreti"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Medina, Matias Eduardo. Centro de Estudios Históricos "Profesor Carlos S. A. Segreti"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin